git.ozlabs.org Git - ccan/blob - ccan/tdb2/test/layout.c

   1 /* TDB tools to create various canned database layouts. */
   2 #include "layout.h"
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <assert.h>
   6
   7 struct tdb_layout *new_tdb_layout(void)
   8 {
   9         struct tdb_layout *layout = malloc(sizeof(*layout));
  10         layout->num_elems = 0;
  11         layout->elem = NULL;
  12         layout->ftable = layout->htable = -1;
  13         return layout;
  14 }
  15
  16 static void add(struct tdb_layout *layout, union tdb_layout_elem elem)
  17 {
  18         layout->elem = realloc(layout->elem,
  19                                sizeof(layout->elem[0])
  20                                * (layout->num_elems+1));
  21         layout->elem[layout->num_elems++] = elem;
  22 }
  23
  24 void tdb_layout_add_free(struct tdb_layout *layout, tdb_len_t len)
  25 {
  26         union tdb_layout_elem elem;
  27         elem.base.type = FREE;
  28         elem.free.len = len;
  29         add(layout, elem);
  30 }
  31
  32 static struct tdb_data dup_key(struct tdb_data key)
  33 {
  34         struct tdb_data ret;
  35         ret.dsize = key.dsize;
  36         ret.dptr = malloc(ret.dsize);
  37         memcpy(ret.dptr, key.dptr, ret.dsize);
  38         return ret;
  39 }
  40
  41 void tdb_layout_add_used(struct tdb_layout *layout,
  42                          TDB_DATA key, TDB_DATA data,
  43                          tdb_len_t extra)
  44 {
  45         union tdb_layout_elem elem;
  46         elem.base.type = DATA;
  47         elem.used.key = dup_key(key);
  48         elem.used.data = dup_key(data);
  49         elem.used.extra = extra;
  50         add(layout, elem);
  51 }
  52
  53 void tdb_layout_add_hashtable(struct tdb_layout *layout,
  54                               unsigned int hash_bits,
  55                               tdb_len_t extra)
  56 {
  57         union tdb_layout_elem elem;
  58         elem.base.type = HASHTABLE;
  59         elem.hashtable.hash_bits = hash_bits;
  60         elem.hashtable.extra = extra;
  61         assert(layout->htable == -1U);
  62         layout->htable = layout->num_elems;
  63         add(layout, elem);
  64 }
  65
  66 void tdb_layout_add_freetable(struct tdb_layout *layout,
  67                               unsigned int num_zones,
  68                               unsigned int zone_bits,
  69                               unsigned int num_buckets,
  70                               tdb_len_t extra)
  71 {
  72         union tdb_layout_elem elem;
  73         elem.base.type = FREETABLE;
  74         elem.freetable.num_zones = num_zones;
  75         elem.freetable.zone_bits = zone_bits;
  76         elem.freetable.num_buckets = num_buckets;
  77         elem.freetable.extra = extra;
  78         assert(layout->ftable == -1U);
  79         layout->ftable = layout->num_elems;
  80         add(layout, elem);
  81 }
  82
  83 static tdb_len_t free_record_len(tdb_len_t len)
  84 {
  85         return sizeof(struct tdb_used_record) + len;
  86 }
  87
  88 static tdb_len_t data_record_len(struct tle_used *used)
  89 {
  90         tdb_len_t len;
  91         len = sizeof(struct tdb_used_record)
  92                 + used->key.dsize + used->data.dsize + used->extra;
  93         assert(len >= sizeof(struct tdb_free_record));
  94         return len;
  95 }
  96
  97 static tdb_len_t hashtable_len(struct tle_hashtable *htable)
  98 {
  99         return sizeof(struct tdb_used_record)
 100                 + (sizeof(tdb_off_t) << htable->hash_bits);
 101 }
 102
 103 static tdb_len_t freetable_len(struct tle_freetable *ftable)
 104 {
 105         return sizeof(struct tdb_used_record)
 106                 + (sizeof(tdb_off_t) * ftable->num_zones
 107                    * (ftable->num_buckets + 1));
 108 }
 109
 110 static void set_free_record(void *mem, tdb_len_t len)
 111 {
 112         /* We do all the work in add_to_freetable */
 113 }
 114
 115 static void set_data_record(void *mem, struct tdb_context *tdb,
 116                             struct tle_used *used)
 117 {
 118         struct tdb_used_record *u = mem;
 119
 120         set_header(tdb, u, used->key.dsize, used->data.dsize,
 121                    used->key.dsize + used->data.dsize + used->extra,
 122                    tdb_hash(tdb, used->key.dptr, used->key.dsize));
 123         memcpy(u + 1, used->key.dptr, used->key.dsize);
 124         memcpy((char *)(u + 1) + used->key.dsize,
 125                used->data.dptr, used->data.dsize);
 126 }
 127
 128 static void set_hashtable(void *mem, struct tdb_context *tdb,
 129                           struct tle_hashtable *htable)
 130 {
 131         struct tdb_used_record *u = mem;
 132         tdb_len_t len = sizeof(tdb_off_t) << htable->hash_bits;
 133
 134         set_header(tdb, u, 0, len, len + htable->extra, 0);
 135         memset(u + 1, 0, len);
 136 }
 137
 138 static void set_freetable(void *mem, struct tdb_context *tdb,
 139                           struct tle_freetable *ftable)
 140 {
 141         struct tdb_used_record *u = mem;
 142         tdb_len_t len = sizeof(tdb_off_t) * ftable->num_zones
 143                 * (ftable->num_buckets + 1);
 144         set_header(tdb, u, 0, len, len + ftable->extra, 0);
 145         memset(u + 1, 0, len);
 146 }
 147
 148 static void add_to_freetable(struct tdb_context *tdb,
 149                              tdb_off_t eoff,
 150                              tdb_off_t elen)
 151 {
 152         add_free_record(tdb, eoff, sizeof(struct tdb_used_record) + elen);
 153 }
 154
 155 static tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
 156 {
 157         return tdb->header.v.hash_off
 158                 + ((list & ((1ULL << tdb->header.v.hash_bits) - 1))
 159                    * sizeof(tdb_off_t));
 160 }
 161
 162 static void add_to_hashtable(struct tdb_context *tdb,
 163                              tdb_off_t eoff,
 164                              struct tdb_data key)
 165 {
 166         uint64_t hash = tdb_hash(tdb, key.dptr, key.dsize);
 167         tdb_off_t hoff;
 168
 169         while (tdb_read_off(tdb, hoff = hash_off(tdb, hash)) != 0)
 170                 hash++;
 171
 172         tdb_write_off(tdb, hoff, eoff);
 173 }
 174
 175 /* FIXME: Support TDB_CONVERT */
 176 struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 177 {
 178         unsigned int i;
 179         tdb_off_t len;
 180         struct tdb_header *hdr;
 181         char *mem;
 182         struct tdb_context *tdb;
 183
 184         assert(layout->ftable != -1U);
 185         assert(layout->htable != -1U);
 186
 187         len = sizeof(struct tdb_header);
 188
 189         /* First pass of layout: calc lengths */
 190         for (i = 0; i < layout->num_elems; i++) {
 191                 union tdb_layout_elem *e = &layout->elem[i];
 192                 e->base.off = len;
 193                 switch (e->base.type) {
 194                 case FREE:
 195                         len += free_record_len(e->free.len);
 196                         break;
 197                 case DATA:
 198                         len += data_record_len(&e->used);
 199                         break;
 200                 case HASHTABLE:
 201                         len += hashtable_len(&e->hashtable);
 202                         break;
 203                 case FREETABLE:
 204                         len += freetable_len(&e->freetable);
 205                         break;
 206                 }
 207         }
 208
 209         mem = malloc(len);
 210         /* Now populate our header, cribbing from a real TDB header. */
 211         tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, NULL);
 212         hdr = (void *)mem;
 213         *hdr = tdb->header;
 214         hdr->v.generation++;
 215         hdr->v.num_zones = layout->elem[layout->ftable].freetable.num_zones;
 216         hdr->v.zone_bits = layout->elem[layout->ftable].freetable.zone_bits;
 217         hdr->v.free_buckets
 218                 = layout->elem[layout->ftable].freetable.num_buckets;
 219         hdr->v.free_off = layout->elem[layout->ftable].base.off
 220                 + sizeof(struct tdb_used_record);
 221         hdr->v.hash_bits = layout->elem[layout->htable].hashtable.hash_bits;
 222         hdr->v.hash_off = layout->elem[layout->htable].base.off
 223                 + sizeof(struct tdb_used_record);
 224
 225         /* Mug the tdb we have to make it use this. */
 226         free(tdb->map_ptr);
 227         tdb->map_ptr = mem;
 228         tdb->map_size = len;
 229         header_changed(tdb);
 230
 231         for (i = 0; i < layout->num_elems; i++) {
 232                 union tdb_layout_elem *e = &layout->elem[i];
 233                 switch (e->base.type) {
 234                 case FREE:
 235                         set_free_record(mem + e->base.off, e->free.len);
 236                         break;
 237                 case DATA:
 238                         set_data_record(mem + e->base.off, tdb, &e->used);
 239                         break;
 240                 case HASHTABLE:
 241                         set_hashtable(mem + e->base.off, tdb, &e->hashtable);
 242                         break;
 243                 case FREETABLE:
 244                         set_freetable(mem + e->base.off, tdb, &e->freetable);
 245                         break;
 246                 }
 247         }
 248
 249         /* Now fill the free and hash tables. */
 250         for (i = 0; i < layout->num_elems; i++) {
 251                 union tdb_layout_elem *e = &layout->elem[i];
 252                 switch (e->base.type) {
 253                 case FREE:
 254                         add_to_freetable(tdb, e->base.off, e->free.len);
 255                         break;
 256                 case DATA:
 257                         add_to_hashtable(tdb, e->base.off, e->used.key);
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262         }
 263
 264         return tdb;
 265 }